DESCRIPTION

The digest functions output the message digest of a supplied file or files
in hexadecimal form. They can also be used for digital signing and verification.

OPTIONS

Tag

Description

-c

print out the digest in two digit groups separated by colons, only relevant if
hex format output is used.

-d

print out BIO debugging information.

-hex

digest is to be output as a hex dump. This is the default case for a normal
digest as opposed to a digital signature.

-binary

output the digest or signature in binary form.

-out filename

filename to output to, or standard output by default.

-sign filename

digitally sign the digest using the private key in filename.

-passin arg

the private key password source. For more information about the format of arg
see the PASSPHRASEARGUMENTS section in openssl(1).

-verify filename

verify the signature using the the public key in filename.
The output is either Verification OK or Verification Failure.

-prverify filename

verify the signature using the the private key in filename.

-signature filename

the actual signature to verify.

-rand file(s)

a file or files containing random data used to seed the random number
generator, or an EGD socket (see RAND_egd(3)).
Multiple files can be specified separated by a OS-dependent character.
The separator is ; for MS-Windows, , for OpenVMS, and : for
all others.

file...

file or files to digest. If no files are specified then standard input is
used.

NOTES

The digest of choice for all new applications is SHA1. Other digests are
however still widely used.

If you wish to sign or verify data using the DSA algorithm then the dss1
digest must be used.

A source of random numbers is required for certain signing algorithms, in
particular DSA.

The signing and verify options should only be used if a single file is
being signed or verified.